The eclipse will be one of the most digitally recorded events ever.

If you’ve never seen a solar eclipse before, you should make an effort to witness the breathtaking event on August 21. While only people in the US will be able to see the total eclipse – in which the moon completely blocks the light from the sun – those living in parts of South America, Africa and Europe should be able to see at least a partial solar eclipse.

Solar eclipses occur when the moon passes between the Earth and the sun so that it blocks part or all of the sunlight as viewed from a particular location on our planet. Earth is the only planet in the solar system where this can happen in this way. This is because of the moon’s size and its relative distance from the sun – when viewed from the Earth, it can identically cover the bright solar disc to reveal the tenuous, wispy outer atmosphere of the star (called the solar corona).

An eclipse does not happen every time the moon travels around the Earth. This is because its orbit has a slight inclination (about five degrees) relative to our planet’s journey around the sun. However when aligned correctly, the result is an awesome, emotional experience. Once the eclipse has begun, the moon continues to eat its way across the blazing sun before darkness falls, the temperature drops and the sky is dominated by a radiant crown around the moon. It happens approximately every 18 months.

During an eclipse the sun’s corona becomes visible to observers on Earth. NASA

On August 21, the moon’s shadow will travel West to East, touching land at Lincoln Beach, Oregon at 09:05 Pacific Daylight Time before speeding across North America at up to 1 km per second and finally exiting close to Charleston, South Carolina, at 16:09 Eastern Daylight Time. The longest total eclipse will occur close to the town of Carbondale, Illinois – lasting about two minutes and 40 seconds.

Anywhere within the 110 km wide path of the eclipse, observers will be able to see the sun completely covered. Outside of that, sky-watchers will still see a partial eclipse with decreasing percentages of the sun’s surface covered as one moves away from this narrow corridor. It is estimated that over 12 million Americans live in the path of the total eclipse itself and another 200 million people within a day’s drive of it. This is science engagement on an unprecedented scale and is likely to be the most orchestrated eclipse viewing event ever undertaken.

Digital deluge

Social media activity has been increasing for months now, building up the anticipation to be part of this rare event. Expect Twitter, Facebook, Snapchat, Flickr and Instagram to be swamped with eclipse pictures during and after the event. In fact, the eclipse should be one of the most digitally recorded events ever, which could be of use to scientists. The Citizen CATE (Continental-America Telescopic Eclipse) experiment aims to capture images of the inner solar corona using a network of more than 60 telescopes operated by citizen scientists, high school groups and universities.

Similarly, the Eclipse Mega-movie is asking observers to use their app to upload eclipse images along the path of totality to produce an expanded and continuous film of the total eclipse as it crosses the country. Both of these experiments will produce unique data-sets of the white light corona, a region that is usually impossible to observe because the exceptionally bright solar disc hides it from view. We will be able to examine like never before the detailed structure of the solar corona and how it is dragged out into space by the solar wind.

There is also a big focus on education. A top priority is making sure that people know how to safely view the eclipse. Looking directly at the sun is unsafe except during that brief period of the total eclipse. It is vitally important that only special solar filters, such as certified eclipse glasses, are used. Unfiltered cameras, telescopes, binoculars or other optical devices concentrate the solar rays and are a definite no-go in regard to eye safety. If no filters are available, it is best to use a pinhole camera to project the eclipse indirectly.

It is also important to take advantage of the amazing opportunity to inform a huge population about the science behind the event. There are thousands of astronomy-oriented events, parties even, being hosted along the path of totality.

New science?

Scientists are equally excited. Eleven NASA and NOAA satellites, high-altitude balloons, hundreds of ground-based telescopes and even the International Space Station will all take advantage of this unique shadow-chase across the surface of the Earth. However, it is not just looking up at the moon and sun that is important. Total eclipses also provide us with an unprecedented opportunity to examine our own planet under quite unusual conditions.

NASA says that observers across several states will measure the radiant energy from the sun into the Earth’s atmosphere from the ground as well as from space. This should provide new insights into how the incident solar energy in our atmosphere changes when particles, clouds and in this case the moon, prevents sunlight from reaching the surface of the planet.

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I will be fortunate enough to be part of a four-hour live online telecast of the eclipse from Carbondale via NASA’s video podcast EDGE. This will include interviews with scientists and live panel questions, high-resolution sun images and a balloon launch. As a solar physicist who can only usually observe the solar corona from space by satellite instrumentation, it is special to be able to glimpse the corona with the (protected) naked eye for a brief time.

One interesting part to all this is the fact that the US gets another chance in seven years to maximise the opportunities that the eclipse brings.

It is said that one of the longlasting legacies of the Apollo missions to the moon is the number of American scientists today who were inspired to be engineers and scientists. Though this solar eclipse is science engagement in a different manner, the end goal is the same – bringing about not just a greater appreciation of the Earth, and solar or lunar research, but also sparking a desire in many young people to be the science leaders of the future.

Adopting three simple habits can help maximise the benefits of existing sanitation infrastructure.

India’s sanitation problem is well documented – the country was recently declared as having the highest number of people living without basic sanitation facilities. Sanitation encompasses all conditions relating to public health - especially sewage disposal and access to clean drinking water. Due to associated losses in productivity caused by sickness, increased healthcare costs and increased mortality, India recorded a loss of 5.2% of its GDP to poor sanitation in 2015. As tremendous as the economic losses are, the on-ground, human consequences of poor sanitation are grim - about one in 10 deaths, according to the World Bank.

Poor sanitation contributes to about 10% of the world’s disease burden and is linked to even those diseases that may not present any correlation at first. For example, while lack of nutrition is a direct cause of anaemia, poor sanitation can contribute to the problem by causing intestinal diseases which prevent people from absorbing nutrition from their food. In fact, a study found a correlation between improved sanitation and reduced prevalence of anaemia in 14 Indian states. Diarrhoeal diseases, the most well-known consequence of poor sanitation, are the third largest cause of child mortality in India. They are also linked to undernutrition and stunting in children - 38% of Indian children exhibit stunted growth. Improved sanitation can also help reduce prevalence of neglected tropical diseases (NTDs). Though not a cause of high mortality rate, NTDs impair physical and cognitive development, contribute to mother and child illness and death and affect overall productivity. NTDs caused by parasitic worms - such as hookworms, whipworms etc. - infect millions every year and spread through open defecation. Improving toilet access and access to clean drinking water can significantly boost disease control programmes for diarrhoea, NTDs and other correlated conditions.

Unfortunately, with about 732 million people who have no access to toilets, India currently accounts for more than half of the world population that defecates in the open. India also accounts for the largest rural population living without access to clean water. Only 16% of India’s rural population is currently served by piped water.

However, there is cause for optimism. In the three years of Swachh Bharat Abhiyan, the country’s sanitation coverage has risen from 39% to 65% and eight states and Union Territories have been declared open defecation free. But lasting change cannot be ensured by the proliferation of sanitation infrastructure alone. Ensuring the usage of toilets is as important as building them, more so due to the cultural preference for open defecation in rural India.

According to the World Bank, hygiene promotion is essential to realise the potential of infrastructure investments in sanitation. Behavioural intervention is most successful when it targets few behaviours with the most potential for impact. An area of public health where behavioural training has made an impact is WASH - water, sanitation and hygiene - a key issue of UN Sustainable Development Goal 6. Compliance to WASH practices has the potential to reduce illness and death, poverty and improve overall socio-economic development. The UN has even marked observance days for each - World Water Day for water (22 March), World Toilet Day for sanitation (19 November) and Global Handwashing Day for hygiene (15 October).

At its simplest, the benefits of WASH can be availed through three simple habits that safeguard against disease - washing hands before eating, drinking clean water and using a clean toilet. Handwashing and use of toilets are some of the most important behavioural interventions that keep diarrhoeal diseases from spreading, while clean drinking water is essential to prevent water-borne diseases and adverse health effects of toxic contaminants. In India, Hindustan Unilever Limited launched the Swachh Aadat Swachh Bharat initiative, a WASH behaviour change programme, to complement the Swachh Bharat Abhiyan. Through its on-ground behaviour change model, SASB seeks to promote the three basic WASH habits to create long-lasting personal hygiene compliance among the populations it serves.

This touching film made as a part of SASB’s awareness campaign shows how lack of knowledge of basic hygiene practices means children miss out on developmental milestones due to preventable diseases.

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SASB created the Swachhata curriculum, a textbook to encourage adoption of personal hygiene among school going children. It makes use of conceptual learning to teach primary school students about cleanliness, germs and clean habits in an engaging manner. Swachh Basti is an extensive urban outreach programme for sensitising urban slum residents about WASH habits through demos, skits and etc. in partnership with key local stakeholders such as doctors, anganwadi workers and support groups. In Ghatkopar, Mumbai, HUL built the first-of-its-kind Suvidha Centre - an urban water, hygiene and sanitation community centre. It provides toilets, handwashing and shower facilities, safe drinking water and state-of-the-art laundry operations at an affordable cost to about 1,500 residents of the area.

HUL’s factory workers also act as Swachhata Doots, or messengers of change who teach the three habits of WASH in their own villages. This mobile-led rural behaviour change communication model also provides a volunteering opportunity to those who are busy but wish to make a difference. A toolkit especially designed for this purpose helps volunteers approach, explain and teach people in their immediate vicinity - their drivers, cooks, domestic helps etc. - about the three simple habits for better hygiene. This helps cast the net of awareness wider as regular interaction is conducive to habit formation. To learn more about their volunteering programme, click here. To learn more about the Swachh Aadat Swachh Bharat initiative, click here.

This article was produced by the Scroll marketing team on behalf of Hindustan Unilever and not by the Scroll editorial team.